Qatar announces plans to buy up to 100 Boeing jets.

QATAR Airways has announced plans to buy up to 100 Boeing aircraft worth $US18.6 billion at list prices, including 30 787-9 Dreamliners and 10 777-300ERs.

The expanding Gulf carrier’s announcement of the $US11.7 billion order for the 787s and 777s increases its firm order backlog for Boeing widebody planes from 66 to 105, including 60 777Xs.

It also signed a letter of intent at a ceremony in Washington, DC attended by government and airline officials, for up 60 737 MAX 8s with a list price of $US6.9 billion.

 Although airlines receive substantial discounts to list prices, the announcement comes at a time sales of widebody jets have slowed. It is also the biggest 787 order since 2013.

Qatar currently has a fleet of 84 Boeing 777s and 787s delivered since it renewed its relationship with the US manufacturer in 2006. The airline was the first in the Middle east to operate the 787 and is the launch customer for the 777X. If the letter of intent progresses to a firm order, the 737MAX will be the first Boeing single aisle plane to join Qatar for 15 years.

"Qatar Airways, already one of the fastest growing airlines in the history of aviation, today announces a significant and historic aircraft order that will power our future growth for the years and the decades ahead," said Qatar Airways Group chief executive Akbar Al Baker said in a statement. "Boeing has proven to be a valuable partner, and today's announcement is testament to our appreciation of the quality of their product and their dedication to providing world class customer service."

Qatar’s total fleet of 190 aircraft includes Airbus A380, A350, A330, A340 and A320 family aircraft. It also has 50 Airbus A320 neos, the competitor to the 737 MAX, on order.

But Boeing Commercial Airplanes president Ray Conner said the deal expressed confidence in Boeing’s new technology aircraft.

"Our partnership with Qatar Airways has grown and strengthened tremendously over the years and I look forward to the time when its fleet will feature an increasing number of both our single and twin-aisle airplanes," he said.

Al Baker denied the commercial aircraft sale was linked to US government approval to allow Boeing to sell 36 F-15E jet fighters worth an estimated $US 4 billion to the Qatar government,  The Seattle Times reported.